From 9ef7fa507d6b53a96de4da3298c5f01bde603c0a Mon Sep 17 00:00:00 2001 From: Douglas Anderson Date: Tue, 4 Dec 2018 19:38:25 -0800 Subject: kgdb: Remove irq flags from roundup The function kgdb_roundup_cpus() was passed a parameter that was documented as: > the flags that will be used when restoring the interrupts. There is > local_irq_save() call before kgdb_roundup_cpus(). Nobody used those flags. Anyone who wanted to temporarily turn on interrupts just did local_irq_enable() and local_irq_disable() without looking at them. So we can definitely remove the flags. Signed-off-by: Douglas Anderson Cc: Vineet Gupta Cc: Russell King Cc: Catalin Marinas Cc: Will Deacon Cc: Richard Kuo Cc: Ralf Baechle Cc: Paul Burton Cc: James Hogan Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Michael Ellerman Cc: Yoshinori Sato Cc: Rich Felker Cc: "David S. Miller" Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Borislav Petkov Cc: "H. Peter Anvin" Acked-by: Will Deacon Signed-off-by: Daniel Thompson --- arch/arm64/kernel/kgdb.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/arm64') diff --git a/arch/arm64/kernel/kgdb.c b/arch/arm64/kernel/kgdb.c index a20de58061a8..12c339ff6e75 100644 --- a/arch/arm64/kernel/kgdb.c +++ b/arch/arm64/kernel/kgdb.c @@ -289,7 +289,7 @@ static void kgdb_call_nmi_hook(void *ignored) kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs()); } -void kgdb_roundup_cpus(unsigned long flags) +void kgdb_roundup_cpus(void) { local_irq_enable(); smp_call_function(kgdb_call_nmi_hook, NULL, 0); -- cgit v1.2.3 From 3cd99ac3559855f69afbc1d5080e17eaa12394ff Mon Sep 17 00:00:00 2001 From: Douglas Anderson Date: Tue, 4 Dec 2018 19:38:26 -0800 Subject: kgdb: Fix kgdb_roundup_cpus() for arches who used smp_call_function() When I had lockdep turned on and dropped into kgdb I got a nice splat on my system. Specifically it hit: DEBUG_LOCKS_WARN_ON(current->hardirq_context) Specifically it looked like this: sysrq: SysRq : DEBUG ------------[ cut here ]------------ DEBUG_LOCKS_WARN_ON(current->hardirq_context) WARNING: CPU: 0 PID: 0 at .../kernel/locking/lockdep.c:2875 lockdep_hardirqs_on+0xf0/0x160 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.19.0 #27 pstate: 604003c9 (nZCv DAIF +PAN -UAO) pc : lockdep_hardirqs_on+0xf0/0x160 ... Call trace: lockdep_hardirqs_on+0xf0/0x160 trace_hardirqs_on+0x188/0x1ac kgdb_roundup_cpus+0x14/0x3c kgdb_cpu_enter+0x53c/0x5cc kgdb_handle_exception+0x180/0x1d4 kgdb_compiled_brk_fn+0x30/0x3c brk_handler+0x134/0x178 do_debug_exception+0xfc/0x178 el1_dbg+0x18/0x78 kgdb_breakpoint+0x34/0x58 sysrq_handle_dbg+0x54/0x5c __handle_sysrq+0x114/0x21c handle_sysrq+0x30/0x3c qcom_geni_serial_isr+0x2dc/0x30c ... ... irq event stamp: ...45 hardirqs last enabled at (...44): [...] __do_softirq+0xd8/0x4e4 hardirqs last disabled at (...45): [...] el1_irq+0x74/0x130 softirqs last enabled at (...42): [...] _local_bh_enable+0x2c/0x34 softirqs last disabled at (...43): [...] irq_exit+0xa8/0x100 ---[ end trace adf21f830c46e638 ]--- Looking closely at it, it seems like a really bad idea to be calling local_irq_enable() in kgdb_roundup_cpus(). If nothing else that seems like it could violate spinlock semantics and cause a deadlock. Instead, let's use a private csd alongside smp_call_function_single_async() to round up the other CPUs. Using smp_call_function_single_async() doesn't require interrupts to be enabled so we can remove the offending bit of code. In order to avoid duplicating this across all the architectures that use the default kgdb_roundup_cpus(), we'll add a "weak" implementation to debug_core.c. Looking at all the people who previously had copies of this code, there were a few variants. I've attempted to keep the variants working like they used to. Specifically: * For arch/arc we passed NULL to kgdb_nmicallback() instead of get_irq_regs(). * For arch/mips there was a bit of extra code around kgdb_nmicallback() NOTE: In this patch we will still get into trouble if we try to round up a CPU that failed to round up before. We'll try to round it up again and potentially hang when we try to grab the csd lock. That's not new behavior but we'll still try to do better in a future patch. Suggested-by: Daniel Thompson Signed-off-by: Douglas Anderson Cc: Vineet Gupta Cc: Russell King Cc: Catalin Marinas Cc: Will Deacon Cc: Richard Kuo Cc: Ralf Baechle Cc: Paul Burton Cc: James Hogan Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Michael Ellerman Cc: Yoshinori Sato Cc: Rich Felker Cc: "David S. Miller" Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Borislav Petkov Cc: "H. Peter Anvin" Acked-by: Will Deacon Signed-off-by: Daniel Thompson --- arch/arc/kernel/kgdb.c | 10 ++-------- arch/arm/kernel/kgdb.c | 12 ------------ arch/arm64/kernel/kgdb.c | 12 ------------ arch/hexagon/kernel/kgdb.c | 27 --------------------------- arch/mips/kernel/kgdb.c | 9 +-------- arch/powerpc/kernel/kgdb.c | 4 ++-- arch/sh/kernel/kgdb.c | 12 ------------ include/linux/kgdb.h | 15 +++++++++++++-- kernel/debug/debug_core.c | 41 +++++++++++++++++++++++++++++++++++++++++ 9 files changed, 59 insertions(+), 83 deletions(-) (limited to 'arch/arm64') diff --git a/arch/arc/kernel/kgdb.c b/arch/arc/kernel/kgdb.c index 0932851028e0..68d9fe4b5aa7 100644 --- a/arch/arc/kernel/kgdb.c +++ b/arch/arc/kernel/kgdb.c @@ -192,18 +192,12 @@ void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long ip) instruction_pointer(regs) = ip; } -static void kgdb_call_nmi_hook(void *ignored) +void kgdb_call_nmi_hook(void *ignored) { + /* Default implementation passes get_irq_regs() but we don't */ kgdb_nmicallback(raw_smp_processor_id(), NULL); } -void kgdb_roundup_cpus(void) -{ - local_irq_enable(); - smp_call_function(kgdb_call_nmi_hook, NULL, 0); - local_irq_disable(); -} - struct kgdb_arch arch_kgdb_ops = { /* breakpoint instruction: TRAP_S 0x3 */ #ifdef CONFIG_CPU_BIG_ENDIAN diff --git a/arch/arm/kernel/kgdb.c b/arch/arm/kernel/kgdb.c index f21077b077be..d9a69e941463 100644 --- a/arch/arm/kernel/kgdb.c +++ b/arch/arm/kernel/kgdb.c @@ -170,18 +170,6 @@ static struct undef_hook kgdb_compiled_brkpt_hook = { .fn = kgdb_compiled_brk_fn }; -static void kgdb_call_nmi_hook(void *ignored) -{ - kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs()); -} - -void kgdb_roundup_cpus(void) -{ - local_irq_enable(); - smp_call_function(kgdb_call_nmi_hook, NULL, 0); - local_irq_disable(); -} - static int __kgdb_notify(struct die_args *args, unsigned long cmd) { struct pt_regs *regs = args->regs; diff --git a/arch/arm64/kernel/kgdb.c b/arch/arm64/kernel/kgdb.c index 12c339ff6e75..da880247c734 100644 --- a/arch/arm64/kernel/kgdb.c +++ b/arch/arm64/kernel/kgdb.c @@ -284,18 +284,6 @@ static struct step_hook kgdb_step_hook = { .fn = kgdb_step_brk_fn }; -static void kgdb_call_nmi_hook(void *ignored) -{ - kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs()); -} - -void kgdb_roundup_cpus(void) -{ - local_irq_enable(); - smp_call_function(kgdb_call_nmi_hook, NULL, 0); - local_irq_disable(); -} - static int __kgdb_notify(struct die_args *args, unsigned long cmd) { struct pt_regs *regs = args->regs; diff --git a/arch/hexagon/kernel/kgdb.c b/arch/hexagon/kernel/kgdb.c index 012e0e230ac2..b95d12038a4e 100644 --- a/arch/hexagon/kernel/kgdb.c +++ b/arch/hexagon/kernel/kgdb.c @@ -115,33 +115,6 @@ void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc) instruction_pointer(regs) = pc; } -#ifdef CONFIG_SMP - -/** - * kgdb_roundup_cpus - Get other CPUs into a holding pattern - * - * On SMP systems, we need to get the attention of the other CPUs - * and get them be in a known state. This should do what is needed - * to get the other CPUs to call kgdb_wait(). Note that on some arches, - * the NMI approach is not used for rounding up all the CPUs. For example, - * in case of MIPS, smp_call_function() is used to roundup CPUs. - * - * On non-SMP systems, this is not called. - */ - -static void hexagon_kgdb_nmi_hook(void *ignored) -{ - kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs()); -} - -void kgdb_roundup_cpus(void) -{ - local_irq_enable(); - smp_call_function(hexagon_kgdb_nmi_hook, NULL, 0); - local_irq_disable(); -} -#endif - /* Not yet working */ void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, diff --git a/arch/mips/kernel/kgdb.c b/arch/mips/kernel/kgdb.c index 2b05effc17b4..42f057a6c215 100644 --- a/arch/mips/kernel/kgdb.c +++ b/arch/mips/kernel/kgdb.c @@ -207,7 +207,7 @@ void arch_kgdb_breakpoint(void) ".set\treorder"); } -static void kgdb_call_nmi_hook(void *ignored) +void kgdb_call_nmi_hook(void *ignored) { mm_segment_t old_fs; @@ -219,13 +219,6 @@ static void kgdb_call_nmi_hook(void *ignored) set_fs(old_fs); } -void kgdb_roundup_cpus(void) -{ - local_irq_enable(); - smp_call_function(kgdb_call_nmi_hook, NULL, 0); - local_irq_disable(); -} - static int compute_signal(int tt) { struct hard_trap_info *ht; diff --git a/arch/powerpc/kernel/kgdb.c b/arch/powerpc/kernel/kgdb.c index b0e804844be0..b4ce54d73337 100644 --- a/arch/powerpc/kernel/kgdb.c +++ b/arch/powerpc/kernel/kgdb.c @@ -117,7 +117,7 @@ int kgdb_skipexception(int exception, struct pt_regs *regs) return kgdb_isremovedbreak(regs->nip); } -static int kgdb_call_nmi_hook(struct pt_regs *regs) +static int kgdb_debugger_ipi(struct pt_regs *regs) { kgdb_nmicallback(raw_smp_processor_id(), regs); return 0; @@ -502,7 +502,7 @@ int kgdb_arch_init(void) old__debugger_break_match = __debugger_break_match; old__debugger_fault_handler = __debugger_fault_handler; - __debugger_ipi = kgdb_call_nmi_hook; + __debugger_ipi = kgdb_debugger_ipi; __debugger = kgdb_debugger; __debugger_bpt = kgdb_handle_breakpoint; __debugger_sstep = kgdb_singlestep; diff --git a/arch/sh/kernel/kgdb.c b/arch/sh/kernel/kgdb.c index cc57630f6bf2..14e012ad7c57 100644 --- a/arch/sh/kernel/kgdb.c +++ b/arch/sh/kernel/kgdb.c @@ -314,18 +314,6 @@ BUILD_TRAP_HANDLER(singlestep) local_irq_restore(flags); } -static void kgdb_call_nmi_hook(void *ignored) -{ - kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs()); -} - -void kgdb_roundup_cpus(void) -{ - local_irq_enable(); - smp_call_function(kgdb_call_nmi_hook, NULL, 0); - local_irq_disable(); -} - static int __kgdb_notify(struct die_args *args, unsigned long cmd) { int ret; diff --git a/include/linux/kgdb.h b/include/linux/kgdb.h index 05e5b2eb0d32..24422865cd18 100644 --- a/include/linux/kgdb.h +++ b/include/linux/kgdb.h @@ -176,14 +176,25 @@ kgdb_arch_handle_exception(int vector, int signo, int err_code, char *remcom_out_buffer, struct pt_regs *regs); +/** + * kgdb_call_nmi_hook - Call kgdb_nmicallback() on the current CPU + * @ignored: This parameter is only here to match the prototype. + * + * If you're using the default implementation of kgdb_roundup_cpus() + * this function will be called per CPU. If you don't implement + * kgdb_call_nmi_hook() a default will be used. + */ + +extern void kgdb_call_nmi_hook(void *ignored); + /** * kgdb_roundup_cpus - Get other CPUs into a holding pattern * * On SMP systems, we need to get the attention of the other CPUs * and get them into a known state. This should do what is needed * to get the other CPUs to call kgdb_wait(). Note that on some arches, - * the NMI approach is not used for rounding up all the CPUs. For example, - * in case of MIPS, smp_call_function() is used to roundup CPUs. + * the NMI approach is not used for rounding up all the CPUs. Normally + * those architectures can just not implement this and get the default. * * On non-SMP systems, this is not called. */ diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c index f3cadda45f07..10db2833a423 100644 --- a/kernel/debug/debug_core.c +++ b/kernel/debug/debug_core.c @@ -55,6 +55,7 @@ #include #include #include +#include #include #include @@ -220,6 +221,46 @@ int __weak kgdb_skipexception(int exception, struct pt_regs *regs) return 0; } +#ifdef CONFIG_SMP + +/* + * Default (weak) implementation for kgdb_roundup_cpus + */ + +static DEFINE_PER_CPU(call_single_data_t, kgdb_roundup_csd); + +void __weak kgdb_call_nmi_hook(void *ignored) +{ + /* + * NOTE: get_irq_regs() is supposed to get the registers from + * before the IPI interrupt happened and so is supposed to + * show where the processor was. In some situations it's + * possible we might be called without an IPI, so it might be + * safer to figure out how to make kgdb_breakpoint() work + * properly here. + */ + kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs()); +} + +void __weak kgdb_roundup_cpus(void) +{ + call_single_data_t *csd; + int this_cpu = raw_smp_processor_id(); + int cpu; + + for_each_online_cpu(cpu) { + /* No need to roundup ourselves */ + if (cpu == this_cpu) + continue; + + csd = &per_cpu(kgdb_roundup_csd, cpu); + csd->func = kgdb_call_nmi_hook; + smp_call_function_single_async(cpu, csd); + } +} + +#endif + /* * Some architectures need cache flushes when we set/clear a * breakpoint: -- cgit v1.2.3 From cc0282975b3f887005c380adcf0af95915f0c1bb Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Thu, 6 Dec 2018 20:07:40 +0000 Subject: kgdb/treewide: constify struct kgdb_arch arch_kgdb_ops checkpatch.pl reports the following: WARNING: struct kgdb_arch should normally be const #28: FILE: arch/mips/kernel/kgdb.c:397: +struct kgdb_arch arch_kgdb_ops = { This report makes sense, as all other ops struct, this one should also be const. This patch does the change. Cc: Vineet Gupta Cc: Russell King Cc: Catalin Marinas Cc: Will Deacon Cc: Yoshinori Sato Cc: Richard Kuo Cc: Michal Simek Cc: Ralf Baechle Cc: Paul Burton Cc: James Hogan Cc: Ley Foon Tan Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Michael Ellerman Cc: Rich Felker Cc: "David S. Miller" Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Borislav Petkov Cc: x86@kernel.org Acked-by: Daniel Thompson Acked-by: Paul Burton Signed-off-by: Christophe Leroy Acked-by: Borislav Petkov Acked-by: Michael Ellerman (powerpc) Signed-off-by: Daniel Thompson --- arch/arc/kernel/kgdb.c | 2 +- arch/arm/kernel/kgdb.c | 2 +- arch/arm64/kernel/kgdb.c | 2 +- arch/h8300/kernel/kgdb.c | 2 +- arch/hexagon/kernel/kgdb.c | 2 +- arch/microblaze/kernel/kgdb.c | 2 +- arch/mips/kernel/kgdb.c | 2 +- arch/nios2/kernel/kgdb.c | 2 +- arch/powerpc/kernel/kgdb.c | 2 +- arch/sh/kernel/kgdb.c | 2 +- arch/sparc/kernel/kgdb_32.c | 2 +- arch/sparc/kernel/kgdb_64.c | 2 +- arch/x86/kernel/kgdb.c | 2 +- include/linux/kgdb.h | 2 +- 14 files changed, 14 insertions(+), 14 deletions(-) (limited to 'arch/arm64') diff --git a/arch/arc/kernel/kgdb.c b/arch/arc/kernel/kgdb.c index 68d9fe4b5aa7..96bca9963c63 100644 --- a/arch/arc/kernel/kgdb.c +++ b/arch/arc/kernel/kgdb.c @@ -198,7 +198,7 @@ void kgdb_call_nmi_hook(void *ignored) kgdb_nmicallback(raw_smp_processor_id(), NULL); } -struct kgdb_arch arch_kgdb_ops = { +const struct kgdb_arch arch_kgdb_ops = { /* breakpoint instruction: TRAP_S 0x3 */ #ifdef CONFIG_CPU_BIG_ENDIAN .gdb_bpt_instr = {0x78, 0x7e}, diff --git a/arch/arm/kernel/kgdb.c b/arch/arm/kernel/kgdb.c index d9a69e941463..6a95b9296640 100644 --- a/arch/arm/kernel/kgdb.c +++ b/arch/arm/kernel/kgdb.c @@ -262,7 +262,7 @@ int kgdb_arch_remove_breakpoint(struct kgdb_bkpt *bpt) * and we handle the normal undef case within the do_undefinstr * handler. */ -struct kgdb_arch arch_kgdb_ops = { +const struct kgdb_arch arch_kgdb_ops = { #ifndef __ARMEB__ .gdb_bpt_instr = {0xfe, 0xde, 0xff, 0xe7} #else /* ! __ARMEB__ */ diff --git a/arch/arm64/kernel/kgdb.c b/arch/arm64/kernel/kgdb.c index da880247c734..ce46c4cdf368 100644 --- a/arch/arm64/kernel/kgdb.c +++ b/arch/arm64/kernel/kgdb.c @@ -345,7 +345,7 @@ void kgdb_arch_exit(void) unregister_die_notifier(&kgdb_notifier); } -struct kgdb_arch arch_kgdb_ops; +const struct kgdb_arch arch_kgdb_ops; int kgdb_arch_set_breakpoint(struct kgdb_bkpt *bpt) { diff --git a/arch/h8300/kernel/kgdb.c b/arch/h8300/kernel/kgdb.c index 1a1d30cb0609..602e478afbd5 100644 --- a/arch/h8300/kernel/kgdb.c +++ b/arch/h8300/kernel/kgdb.c @@ -129,7 +129,7 @@ void kgdb_arch_exit(void) /* Nothing to do */ } -struct kgdb_arch arch_kgdb_ops = { +const struct kgdb_arch arch_kgdb_ops = { /* Breakpoint instruction: trapa #2 */ .gdb_bpt_instr = { 0x57, 0x20 }, }; diff --git a/arch/hexagon/kernel/kgdb.c b/arch/hexagon/kernel/kgdb.c index b95d12038a4e..3fabd3ff3bbd 100644 --- a/arch/hexagon/kernel/kgdb.c +++ b/arch/hexagon/kernel/kgdb.c @@ -83,7 +83,7 @@ struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] = { { "syscall_nr", GDB_SIZEOF_REG, offsetof(struct pt_regs, syscall_nr)}, }; -struct kgdb_arch arch_kgdb_ops = { +const struct kgdb_arch arch_kgdb_ops = { /* trap0(#0xDB) 0x0cdb0054 */ .gdb_bpt_instr = {0x54, 0x00, 0xdb, 0x0c}, }; diff --git a/arch/microblaze/kernel/kgdb.c b/arch/microblaze/kernel/kgdb.c index 6366f69d118e..130cd0f064ce 100644 --- a/arch/microblaze/kernel/kgdb.c +++ b/arch/microblaze/kernel/kgdb.c @@ -143,7 +143,7 @@ void kgdb_arch_exit(void) /* * Global data */ -struct kgdb_arch arch_kgdb_ops = { +const struct kgdb_arch arch_kgdb_ops = { #ifdef __MICROBLAZEEL__ .gdb_bpt_instr = {0x18, 0x00, 0x0c, 0xba}, /* brki r16, 0x18 */ #else diff --git a/arch/mips/kernel/kgdb.c b/arch/mips/kernel/kgdb.c index 71e5073a0d90..149100e1bc7c 100644 --- a/arch/mips/kernel/kgdb.c +++ b/arch/mips/kernel/kgdb.c @@ -387,7 +387,7 @@ int kgdb_arch_handle_exception(int vector, int signo, int err_code, return -1; } -struct kgdb_arch arch_kgdb_ops = { +const struct kgdb_arch arch_kgdb_ops = { #ifdef CONFIG_CPU_BIG_ENDIAN .gdb_bpt_instr = { spec_op << 2, 0x00, 0x00, break_op }, #else diff --git a/arch/nios2/kernel/kgdb.c b/arch/nios2/kernel/kgdb.c index 117859122d1c..37b25f844a2d 100644 --- a/arch/nios2/kernel/kgdb.c +++ b/arch/nios2/kernel/kgdb.c @@ -165,7 +165,7 @@ void kgdb_arch_exit(void) /* Nothing to do */ } -struct kgdb_arch arch_kgdb_ops = { +const struct kgdb_arch arch_kgdb_ops = { /* Breakpoint instruction: trap 30 */ .gdb_bpt_instr = { 0xba, 0x6f, 0x3b, 0x00 }, }; diff --git a/arch/powerpc/kernel/kgdb.c b/arch/powerpc/kernel/kgdb.c index b4ce54d73337..e1865565f0ae 100644 --- a/arch/powerpc/kernel/kgdb.c +++ b/arch/powerpc/kernel/kgdb.c @@ -477,7 +477,7 @@ int kgdb_arch_remove_breakpoint(struct kgdb_bkpt *bpt) /* * Global data */ -struct kgdb_arch arch_kgdb_ops; +const struct kgdb_arch arch_kgdb_ops; static int kgdb_not_implemented(struct pt_regs *regs) { diff --git a/arch/sh/kernel/kgdb.c b/arch/sh/kernel/kgdb.c index 14e012ad7c57..ba0a1687f5cb 100644 --- a/arch/sh/kernel/kgdb.c +++ b/arch/sh/kernel/kgdb.c @@ -370,7 +370,7 @@ void kgdb_arch_exit(void) unregister_die_notifier(&kgdb_notifier); } -struct kgdb_arch arch_kgdb_ops = { +const struct kgdb_arch arch_kgdb_ops = { /* Breakpoint instruction: trapa #0x3c */ #ifdef CONFIG_CPU_LITTLE_ENDIAN .gdb_bpt_instr = { 0x3c, 0xc3 }, diff --git a/arch/sparc/kernel/kgdb_32.c b/arch/sparc/kernel/kgdb_32.c index 639c8e54530a..7580775a14b9 100644 --- a/arch/sparc/kernel/kgdb_32.c +++ b/arch/sparc/kernel/kgdb_32.c @@ -166,7 +166,7 @@ void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long ip) regs->npc = regs->pc + 4; } -struct kgdb_arch arch_kgdb_ops = { +const struct kgdb_arch arch_kgdb_ops = { /* Breakpoint instruction: ta 0x7d */ .gdb_bpt_instr = { 0x91, 0xd0, 0x20, 0x7d }, }; diff --git a/arch/sparc/kernel/kgdb_64.c b/arch/sparc/kernel/kgdb_64.c index a68bbddbdba4..5d6c2d287e85 100644 --- a/arch/sparc/kernel/kgdb_64.c +++ b/arch/sparc/kernel/kgdb_64.c @@ -195,7 +195,7 @@ void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long ip) regs->tnpc = regs->tpc + 4; } -struct kgdb_arch arch_kgdb_ops = { +const struct kgdb_arch arch_kgdb_ops = { /* Breakpoint instruction: ta 0x72 */ .gdb_bpt_instr = { 0x91, 0xd0, 0x20, 0x72 }, }; diff --git a/arch/x86/kernel/kgdb.c b/arch/x86/kernel/kgdb.c index ac6291a4178d..5db08425063e 100644 --- a/arch/x86/kernel/kgdb.c +++ b/arch/x86/kernel/kgdb.c @@ -799,7 +799,7 @@ knl_write: (char *)bpt->saved_instr, BREAK_INSTR_SIZE); } -struct kgdb_arch arch_kgdb_ops = { +const struct kgdb_arch arch_kgdb_ops = { /* Breakpoint instruction: */ .gdb_bpt_instr = { 0xcc }, .flags = KGDB_HW_BREAKPOINT, diff --git a/include/linux/kgdb.h b/include/linux/kgdb.h index 24422865cd18..fbf144aaa749 100644 --- a/include/linux/kgdb.h +++ b/include/linux/kgdb.h @@ -287,7 +287,7 @@ struct kgdb_io { int is_console; }; -extern struct kgdb_arch arch_kgdb_ops; +extern const struct kgdb_arch arch_kgdb_ops; extern unsigned long kgdb_arch_pc(int exception, struct pt_regs *regs); -- cgit v1.2.3